Matrix



. S. c. FORRESTER MATRIX i Oct. 2l, 1930.-

Filed Sept. 9, 1929 Patented @ce 21, 1930 sai/mano. FORRESTER, or Arianna, GEORGIAy Marnix f Application ineaA september e, 192er' serieu Nb.' 331,325.l

Generically this invention relates' to matrices butit more especially comprehends'the type adapted for use in` connectiony with the production of resilient plates adaptable for fine line or half tone/color yprinting on fabrics such as'flour bags and the like. y o

The principal obj ect of this invention is the provision ofa matrix and-process kof making same comprising a metallic facing sheet susceptible of producing type shoulders and depressions of suificient height Yand depth, 're-f spectively, ona printing platetoeffe'ct sharp contours and accurate register in' color and fine line or half-tone printing' `on relatively coarse fabrics such as flour sacks, said metal'- Vlic sheet having applied thereto a non-metallic material, the latter having a backing of metallic material, whereby such backing material may be applied at itsproper temperature for full fluidityandhomogeneous casting without adversely affecting the facing sheet carrying the impression. Y '2 7 Vith these and other objects in view, which will become apparent as the descrip tion proceeds, the inventionresides inthe construction, combination and arrangement of parts, hereinafter more. fully described and claimed, and illustrated in the accompanying drawi'ngs, in which like characters of reference indicate like parts throughout the several figures, of which: Y Fig. l is a transverse sectional view taken through the type form and the impression sheet in Contact therewith Fig. 2 is a similar view with the non-metallic or fibrous material applied to the impression sheet; v Y v Fig. 3 is al vertical section-'through 'the casting. box' and components as' shown in Fig. 2; Fig. Lis a similar view to Fig. 3 after-the introduction of the backing material; rand Y Fig. 5 is a sectional view through the complete matrix. A f

The types of'matrices-of this character heretofore in usepand the `methods of producing same have proven `deficient in the productionof resilient printing plates for line' line color printing on coarse fabrics for many reasons, certain ofasaid methods being' to placca type form with a lead or other lme'tal'- y hc type of impression sheet in contactvthere# within a' horizontal positiona'ndthenpour# composed of lead andk other materialv having a relatively low melting point, so as to become homogeneous with the sheet carrying the im-y pression. However, experience Ahas 'demonstrated that casting stereotypedV metalfin -athin vsheet over a' form in a horizontal posiing on top of' said sheet, after treatment with Y a cleansing and fluxi'ng material', analloy tiondoes not giveV homogeneous results.

And, further, matrices so constructed owing to the difference in meltingpoint between the facing'and backing' metals veffects a suflicient distortion of the `impression sheet or facing to affect the sharp contours of the printing plate produced thereby and prevent accurate n registry in'line'line color printing. Again, other methods consist inpressing into av type face ausoft alloy or foilV facing sheet and backing same with a phenolic substance adapted to harden and set under heat and pressure, and the impression surface of such type of matrix, even though employingV a low melting point facing sheet, bevcomes'distorted during the molding process in the production of resilient printing plates 'sulficient tofpreclude a fine line vcolor register by vthe resilient' printing plate','*and conse-v sov quently, rendering such Vplate incapable of producingy tine line and haljflftone printingv on relatively coarse' fabrics; and it was to overcome the deficiencies of such methods, and kprovide a' matrix capable of producing under heat and pressurea resilient printing plate capableL of effecting fineline half tone color'printing on coarse fabricss'uchas Hour sacks and the like, which "I accomplish by Vmy improvedfmethod of pressing an' alloy.

sheet having a relatively lowvmeltingfpoint into the surface of a type form, applyingan adhesive fibrous-heat resisting backing sheet to said metallic sheet', and then apply'- ing to the fibrous sheet a backing of stereotype metal at its proper temperaturegfor full fluidity and homogenous "castingywith'r:

the fibrous backing in a vertical position dur;

ing the backing process, without: adversely affecting the sheet carrying the impressiom In the illustrated embodiment characterizing this invention there is shown a. matrix A, type, form `or positive pattern plate B, an alloy facing sheet C, fibrous material sheet D, and metallic backing'E, and in carrying out the process of my invention'the facing 'or impression ,alloy sheet C, the meltingl point of which is relatively low, ispressed into the face of type form B, and then'superimposed on said sheet C is a sheet D of brous heat-resisting `material such as cartridge Vpaper or other suitable material, and which, though not always necessary, preferably has its contact surface treated withanladhesive 'tion and allowed to rise .to aheight of several inches above the ylevel of the Vform B, thereby obtaining a `most homogeneous cast `with a relatively high melting point backing,

, g The mass, after the material E has cooled,

' is then removed from the casting boX- F and Atype form B removed, leaving matrix A, and

which matrix thus formed, by Vvirtue of its homogeneous backing is capableof withstanding great pressure, and owing to the -fibrous'rsheet interposed :between said backing andsurface impression sheets is capable of withstanding the heat and pressure inci.

dent to the molding process in the production of resilient printing plates, and of imparting to such printing plate sharp type face fine line contours for ne line, half tone, color printing, whereby perfect i color registrykis eifected. s l s' ,Y

VIt is apparent that bythe above `method I have produced a matrix overcoming the inherent deficiencies ofthose heretofore in Vuse for the production of resilient printing sheet, and which has only been accomplished' after great experimentation.

QFor the Vpurpose, above outlined,` -to suc@ cessfully unite aV molded face sheet with a backing up metal to effect a practically homogeneous vmatrix proved a most dii'iicu-lt operation to solve, since if the backing metal 41s at'a propeivtemperaturei for pouring into acasting b ox itiis so highsthat itwill melt the impression sheet molded onthe'type mat ter, and if the. backing metalis not at this `high temperature it will not flow .freely over the molded sheet and will not .form auhomo-` geneous casting. Through said experimentation it was ,found that such homogeneous casting could not be obtained by merely Vfloating molten metal on the type form containing the molded impression sheet still in contact with the typematter in a horizontal plane, and'was only possible by applying such metalto'the fibrous backed surface of the impression sheet when in a verticalplane, and wherein such :materialY VVwas permitted to -rise above the level of the form. Qther-V wise vit Vis not ahomogeneous :castingunless the metal used forbacking Vis of a very low the Vabove description vas the preferred ein.-

bodimentis the most-eiiicient and practical; yet vrealizing the conditions concurrent with the adoption of my invention will necessarily vary, I desire` to1lempha`s1ze` that', various minor changes in details of construction, pron` portion and arrangement of; parts, may be resortedto within'the scope-ofthe appendf ed claims without "depa'rtingfromor sa`cri-Y ii'cing any of the principles of this invention.

Having thus described my invention, what I desire protectedby Letters Patent is as set forth inthe following claims: f

l. A printingplate matrixvcomprising a design bearing impression sheet, a sheet of non-metallic heat-resisting material, and aV metallic backing material. V 2. A printing plate matrix, comprising a design bearing impressionsheet of moldable material, a sheet of fibrousheatq'esisting material, and a metallic vbacking for said fibrous material. s Y i 3. A'matrix for the productionof resilient printin'grplates, comprising afdesign bearing impression sheet of moldable materiahaV me- `tallic backing material of a melting point different fr om that of the impressionsheet, and a sheetrof heat-,repellant material interposed betweenfthe.V impression and .backing materials. 4.VV A method of'producing a printing plate matrix consisting in subjecting afsheet of moldablevmaterial to'pressure in Contact with a type body to form type-forming depressions and nontype-forming elevations, f then applying ,abacking, of fibrous heat resisting material to said first Vmentioned material, and then applyinga backing offmolten material to the back of thehea't-resisting material and permitting said `molten material yst to harden to form a backing for said heatresisting and moldable materials.

5.v A method of producing a printing plate matrix consisting in forming an impression 4sheet of moldable material With adesign;

then treating the surface of a sheet of .brous heat-resisting material With an adhesive substance, then applying said sheet to the back of' said moldable material With the adhesive surface incontact therewith, and then vapl plying a backing to said fibrous sheet of matalio material of a high melting point in a molten state, and permitting said material V Vto harden to form a solid backing for said fibrous and impression sheets.

.6. A method of producing a printing plate matrix consisting informing 'an vimpression sheet With a design, then applying a sheet of fibrous heat resisting material tothe back of said impression sheet, then placing said type form, impression sheet and fibrous sheet, in a casting box inra Vertical position, then pouring into said casting boxk a metallic material at thep'roper temperature for full fluidity, and permitting such material vtov rise to a point above the level'of the type form, im-

pression and fibrous sheets, and permitting said metal to harden to form a homogeneous backing for said fibrous and impression sheets. i

7. A method of producing a printing platematrix consisting in subjecting a sheet of moldable alloy of low melting point to-presy sure in Contact With a type body to form type forming depressions and non-type forming elevations in the sheet, then applying a sheet of fibrous heat-resisting material to the back of said alloysheet, then placing said type form, moldable impressionv sheet and iibrous sheet, in a casting box in a Vertical position, then pouring into said castingbox'in contact With said fibrous sheet a stereotype metal of high melting point at the proper temperature for full fluidity and allowing said material to rise yabove the level of' said form, impression and fibrous sheets, andy permitting such material to cool toV form a homogeneous backing for said impression and lfibrous sheets Without affecting the moldable impression sheet during the last mentioned backing process.A

This specification signed thisy 31st day of July, A. D. 1929. Y Y

SAMUEL o. FoRREsTER.l 

